In this installment of "Comparatively Speaking," industry expert Tony O'Lenick explains the difference between maceration and decoction.
An earlier column described extraction; this column continues with a related concept. Maceration is the extraction of a active in a solvent with shaking or stirring at room temperature. After a defined period, the spent, solid material is separated from the solution (macerate). On the other hand, decoction is a method of extraction that results from placing a matrix in a menstruum (solvent) that is then heated to boiling. The matrix may include leaves, stems, roots, bark and other plant materials.
Decoction involves mashing and then boiling in water to extract oils, volatile organic compounds and other chemical substances. The process has been used since antiquity for the preparation of traditional medicines. In traditional Chinese medicine, it is customary to place the quantity of herbs required for one day's treatment into a vessel, to which hot or boiling water is added. The vessel is then raised to boiling point and allowed to simmer. The decoction so produced is allowed to cool, separated from solid particles, and the decoction is used as the dosage form for oral administration.
Maceration is used in winemaking and is the process by which the red wine receives its red color. In the production of white wines, maceration is either actively avoided or allowed in a very limited manner in the form of a short amount of skin contact between the must prior to pressing. Maceration can also be used to make limoncello. Decoction is used in making tea. Maceration is generally less aggressive, extracting fewer actives.
A disadvantage of maceration and decoction with water or low concentrations of ethanol is that a large quantity of inert material (ballast) that has no therapeutic value is extracted. Ballast may consist of plant cell constituents including, but not limited to, fats, waxes, carbohydrates, proteins and sugars. This may contribute to microbiological spoilage if the product is not used promptly. If dried, the extracts so produced tend to be hygroscopic and difficult to formulate. The ballast may also affect the way in which the active constituents are absorbed from the finished dosage form.
2 bottles (750 mL) 100-proof vodka**
4 cups sugar
5 cups water
*Choose thick-skinned lemons because they are easier to zest.
** Use 100-proof vodka, which has less flavor than a lower proof one. Also, the high alcohol level will ensure that the limoncello will not turn to ice in the freezer.
Wash the lemons with a vegetable brush and hot water to remove any reside of pesticides or wax; pat the lemons dry. Carefully zest the lemons with a zester or vegetable peeler so there is no white pith on the peel. Note: Use only the outer part of the rind. The pith, the white part underneath the rind, is too bitter and will spoil your limoncello.
Step One: In a large glass jar (1-gallon jar), add one bottle of vodka; add the lemon zest as it is zested. Cover the jar and let sit at room temperature for at least (10) ten days and up to (40) days in a cool dark place. The longer it rests, the better the taste will be. (There is no need to stir; all you have to do is wait.) As the limoncello sits, the vodka slowly take on the flavor and rich yellow color of the lemon zest.
Step Two: In a large saucepan, combine the sugar and water; cook until thickened, approximately 5 to 7 min. Let the syrup cool before adding it to the limoncello mixture. Add to the Limoncello mixture from Step One. Add the additional bottle of vodka. Allow to rest for another 10 to 40 days.
Step Three: After the rest period, strain and bottle, discarding the lemon zest. Keep in the freezer until ready to serve.